Well, it seems that my previous comments about TCPA not being able to secure boot were true, but this work from IBM suggests that it can provide a primitive that says "only decrypt this on a given boot config".
Now, a boot config (my name) is defined loosely in the TCPA specs (site seems to be down right now, maybe MsSQL worm) and I would wish to see exactly what it is hashing before I use it. But I can see many useful applications of this. For one, encrypt the hard drive and store the decryption key in the TCPA chip. That way you get seemless boots, but you cannot root the box with a floppy disk. I can think of a number times that function would have been nice. So I think I would be quite happy to have a TCPA motherboard and I want to see lots of neat uses of them.